Numerical evaluation of mass-diffusive compressible fluids flows models
Bodnár, Tomáš; Fraunié, P.
2024 - anglický
This contribution presents first numerical tests of some recently published alternative models for solution of viscous compressible and nearly incompressible models. All models are solved by high resolution compact finite difference scheme with strong stability preserving RungeKutta time stepping. The two simple but challenging computational test cases are presented, based on the double-periodic shear layer and the Kelvin-Helmholtz instability. The obtained time-dependent flow fields are showing pronounced shear and vorticity layers being resolved by the standard as well as by the new mass-diffusive modified models. The preliminary results show that the new models are viable alternative to the well established classical models.
Klíčová slova:
compressible Navier-Stokes; nearly incompressible flow; mass diffusion; compact finite-difference
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Numerical evaluation of mass-diffusive compressible fluids flows models
This contribution presents first numerical tests of some recently published alternative models for solution of viscous compressible and nearly incompressible models. All models are solved by high ...
Motion of fluids in the moving domain
Nečasová, Šárka
2024 - anglický
It is a survay paper where the problem of the existence of weak solutions of compressible barotropic solutions in a moving bounded domain is studied.
Klíčová slova:
compressible fluid; moving domain; weak solutions
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Motion of fluids in the moving domain
It is a survay paper where the problem of the existence of weak solutions of compressible barotropic solutions in a moving bounded domain is studied.
Financial skills and search in the mortgage market
Cota, Marta; Šterc, Ante
2024 - anglický
Are households with low financial skills disadvantaged in the mortgage market? Using stochastic record linking, we construct a unique U.S. dataset encompassing a rich set of mortgage details and borrowers’ characteristics, including their objective financial literacy measure. We find that households with low financial literacy are up to 4% more likely to search less and lock in at 15-20 b.p. higher rates. Upon origination, unskilled borrowers face a 35-45% higher mortgage delinquency and end up with a 30% lower likelihood of refinancing. Overall, for a $100,000 loan, the potential losses from low financial literacy are more than $9,329 over the mortgage duration. To understand how financial education, more accessible mortgages, or mortgage rate changes affect households with low financial literacy, we formulate and calibrate a mortgage search model with heterogeneous search frictions and endogenous financial skills. Our model estimates show that search intensity and financial skill variations contribute to 55% and 10% of mortgage rate variations, respectively. We find that i) more accessible mortgages lead to a higher delinquency risk among low-skilled households, ii) financial education mitigates the adverse effects of increased accessibility, and iii) low mortgage rates favor high-skilled homeowners and, by reinforcing refinancing activity, deepen consumption differences across different financial skill levels.
Klíčová slova:
mortgage refinancing; mortgage search; financial skills
Dokument je dostupný na externích webových stránkách.
Financial skills and search in the mortgage market
Are households with low financial skills disadvantaged in the mortgage market? Using stochastic record linking, we construct a unique U.S. dataset encompassing a rich set of mortgage details and ...
Modification of cooling system for laboratory measurement of rotor blade vibration
Maturkanič, Dušan; Procházka, Pavel; Hodboď, Robert; Voronova, Evgeniya; Mekhalfia, Mohammed Lamine
2024 - anglický
Last year, the replacement of the turbine wheel model was completed in the Laboratory of Rotational Laser Vibrometry of the Institute of Thermomechanics AS CR, v.v.i. Based on previous experience and the expected higher operating load planned for the new wheel, the cooling system was modified at the same time. The paper describes the main effort in this direction and the results that clarify the previous damage of the measuring device.
Klíčová slova:
blade; vibration; cooling system; measurement; laboratory
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Modification of cooling system for laboratory measurement of rotor blade vibration
Last year, the replacement of the turbine wheel model was completed in the Laboratory of Rotational Laser Vibrometry of the Institute of Thermomechanics AS CR, v.v.i. Based on previous experience and ...
DYNAMICS OF MACHINES AND MECHANICAL SYSTEMS WITH INTERACTIONS : PROCEEDINGS DYMAMESI 2024
Zolotarev, Igor; Pešek, Luděk; Kozień, M. S.
2024 - anglický
The aim of the DYMAMESI is to facilitate the exchange of up to date information and knowledge among specialists in structural and multibody dynamics, in coupled interacting systems as aero-elasticity, hydro-elasticity, biomechanics, systems with feedbacks and mechatronics. In 2023 will be hosted by Cracow University of Technology, Institute of Applied Mechanics, Section of Dynamics of Systems.
Klíčová slova:
dynamics; vibrations of mechanical systems; vibrodiagnostics; energy transformations
Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
DYNAMICS OF MACHINES AND MECHANICAL SYSTEMS WITH INTERACTIONS : PROCEEDINGS DYMAMESI 2024
The aim of the DYMAMESI is to facilitate the exchange of up to date information and knowledge among specialists in structural and multibody dynamics, in coupled interacting systems as aero-elasticity, ...
Stochastic version of the arc-length method
Náprstek, Jiří; Fischer, Cyril
2024 - anglický
The solution of a nonlinear algebraic system using the incremental method, based on pre-defined loading steps, fails in the vicinity of local extrema as well as around bifurcation points. The solution involved the derivation of the so-called ’Arc-Length’ method. Its essence lies in not incrementing the system parameter or any of the independent variables but rather the length of the response curve. The stochastic variant of this method allows for working with a system where system parameters include random imperfections. This contribution presents a variant that tracks the first two stochastic moments. Even in this simple case, interesting phenomena can be observed, such as the disappearance of the energy barrier against equilibrium jump due to random imperfections in the system.
Klíčová slova:
random imperfection; stochastic arc-length method; continuation; numerical method
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Stochastic version of the arc-length method
The solution of a nonlinear algebraic system using the incremental method, based on pre-defined loading steps, fails in the vicinity of local extrema as well as around bifurcation points. The solution ...
Acoustic emission methods in steel bridge degradation identification and monitoring
Šorm, Filip
2024 - anglický
Acoustic emission methods proved to be an effective diagnostic tool in many industrial sectors. The potential of this method in the field of steel bridge diagnostics is explored in this article. The goal is to find the most effective use of this method.
Klíčová slova:
steel bridges; diagnostics; acoustic emission
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Acoustic emission methods in steel bridge degradation identification and monitoring
Acoustic emission methods proved to be an effective diagnostic tool in many industrial sectors. The potential of this method in the field of steel bridge diagnostics is explored in this article. The ...
Multi-Annual Characterization of PM1 Aerosol Optical Properties and Size Distribution at the Peri-Urban Atmospheric Site ATOLL in Lille
Suchánková, Lenka
2024 - anglický
The aim of this study is to present aerosol scattering, absorption properties and particle number size distribution in PM1 in years 2018-\n2022 at peri-urban atmospheric site Atmospheric Observations in LiLLE (ATOLL) in Lille, France. This study is the first to present results dedicated to aerosol scattering properties at this site.
Klíčová slova:
aerosol particles; PM1; temporal trends
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Multi-Annual Characterization of PM1 Aerosol Optical Properties and Size Distribution at the Peri-Urban Atmospheric Site ATOLL in Lille
The aim of this study is to present aerosol scattering, absorption properties and particle number size distribution in PM1 in years 2018-\n2022 at peri-urban atmospheric site Atmospheric Observations ...
Development of Continuous Technology for the Preparation of Pharmaceuticals
Jaklová, Natalie
2024 - anglický
The present research focuses on the transition of a batch reaction assisted by phase transfer catalyst (PTC) into continuous process. The first reaction studied was an N-alkylation reaction with methyl ester of the 1-methyl-10α-methoxydihydrolysergic acid (MeLUME) as product. MeLUME is one of the intermediates in synthesis of drug Nicergoline. The N-alkylation occurs in two different immiscible phases and the bridge between these phases is the phase transfer catalyst. The study was performed in several different continuous flow apparatuses. The best results were obtained in a capillary reactor, with assistance of ultrasound.
Klíčová slova:
continualization; ultrasound; pharmaceuticals
Plné texty jsou dostupné v digitálním repozitáři NUŠL
Development of Continuous Technology for the Preparation of Pharmaceuticals
The present research focuses on the transition of a batch reaction assisted by phase transfer catalyst (PTC) into continuous process. The first reaction studied was an N-alkylation reaction with ...
Bubble Breakup in Triton Solutions
Semlerová, Tereza
2024 - anglický
This work deals with investigation of the bubble breakup in surfactant Triton X-45 solutions and the results are compared with data measured in water and α-terpineol solutions as another type of surfactants.
Klíčová slova:
bubble breakup; surfactants; dynamic surface tension
Plné texty jsou dostupné v digitálním repozitáři Akademie Věd.
Bubble Breakup in Triton Solutions
This work deals with investigation of the bubble breakup in surfactant Triton X-45 solutions and the results are compared with data measured in water and α-terpineol solutions as another type of ...
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